Study of Chitosan for Pharmacologic Manipulation of AGE Levels in Prostate Cancer Patients

Inclusion: 1. Confirmation of adenocarcinoma of the prostate that is documented by one of the following: pathology report or clinic note with documented history of prostate cancer. 2. Subjects must be receiving ADT with a GnRH agonist or antagonist, with or without an anti-androgen or testosterone synthesis inhibitor. The current testosterone level must be documented to be \<50ng/dL at enrollment. Subjects whose ADT is interrupted may enroll or continue on study as long as the testosterone is documented to remain \<50ng/dL for the entire duration of study participation. Subjects who have undergone orchiectomy are also eligible. 3. Subjects must have adequate hematologic, renal, and hepatic function at baseline, as follows: * Hematology parameters: ANC \>1000/mcL, platelets \> 100,000/mcL, Hgb \>8.0gm/dL * Renal Function: eGFR of ≥ 45mls/min using Cockgroft and Gault formula * Liver Function: Total bilirubin ≤ULN, AST and ALT \<1.5x ULN 4. Able to swallow and retain oral medication 5. ECOG performance status of 0 - 2 6. Ability to sign written informed consent 7. Testosterone level \<50ng/dL at time of enrollment. 8. Age 18 or older. 9. May have had prior radiation therapy, surgery, or cryoablation for primary prostate cancer 10. May have had prior cytotoxic chemotherapy for metastatic prostate cancer, prior treatment with genomically-targeted agents, or Provenge Exclusion: 1. Known allergy to chitosan or shellfish. 2. History of receiving more than 2 classes of ADT. 3. Chronic constipation (BM \< 3x weekly), history of malabsorption or history of daily laxative use. 4. Patients requiring medication administration with lunch or dinner or at a frequency of three or more times per day are not eligible. 5. Current use of chitosan, sevelamer, and/or glucosamine.